{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<table class=\"ee-notebook-buttons\" align=\"left\">\n",
    "    <td><a target=\"_blank\"  href=\"https://github.com/giswqs/geemap/tree/master/examples/notebooks/ipyleaflet_draw_control.ipynb\"><img width=32px src=\"https://www.tensorflow.org/images/GitHub-Mark-32px.png\" /> View source on GitHub</a></td>\n",
    "    <td><a target=\"_blank\"  href=\"https://nbviewer.jupyter.org/github/giswqs/geemap/blob/master/examples/notebooks/ipyleaflet_draw_control.ipynb\"><img width=26px src=\"https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Jupyter_logo.svg/883px-Jupyter_logo.svg.png\" />Notebook Viewer</a></td>\n",
    "    <td><a target=\"_blank\"  href=\"https://colab.research.google.com/github/giswqs/geemap/blob/master/examples/notebooks/ipyleaflet_draw_control.ipynb\"><img width=26px src=\"https://www.tensorflow.org/images/colab_logo_32px.png\" /> Run in Google Colab</a></td>\n",
    "</table>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Using ipyleaflet drawing tools to interact with Earth Engine data\n",
    "\n",
    "* [Video demo](https://i.imgur.com/SzauIsZ.gifv)\n",
    "\n",
    "## Install Earth Engine API and geemap\n",
    "Install the [Earth Engine Python API](https://developers.google.com/earth-engine/python_install) and [geemap](https://github.com/giswqs/geemap). The **geemap** Python package is built upon the [ipyleaflet](https://github.com/jupyter-widgets/ipyleaflet) and [folium](https://github.com/python-visualization/folium) packages and implements several methods for interacting with Earth Engine data layers, such as `Map.addLayer()`, `Map.setCenter()`, and `Map.centerObject()`.\n",
    "The following script checks if the geemap package has been installed. If not, it will install geemap, which automatically installs its [dependencies](https://github.com/giswqs/geemap#dependencies), including earthengine-api, folium, and ipyleaflet.\n",
    "\n",
    "**Important note**: A key difference between folium and ipyleaflet is that ipyleaflet is built upon ipywidgets and allows bidirectional communication between the front-end and the backend enabling the use of the map to capture user input, while folium is meant for displaying static data only ([source](https://blog.jupyter.org/interactive-gis-in-jupyter-with-ipyleaflet-52f9657fa7a)). Note that [Google Colab](https://colab.research.google.com/) currently does not support ipyleaflet ([source](https://github.com/googlecolab/colabtools/issues/60#issuecomment-596225619)). Therefore, if you are using geemap with Google Colab, you should use [`import geemap.eefolium`](https://github.com/giswqs/geemap/blob/master/geemap/eefolium.py). If you are using geemap with [binder](https://mybinder.org/) or a local Jupyter notebook server, you can use [`import geemap`](https://github.com/giswqs/geemap/blob/master/geemap/geemap.py), which provides more functionalities for capturing user input (e.g., mouse-clicking and moving)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Installs geemap package\n",
    "import subprocess\n",
    "\n",
    "try:\n",
    "    import geemap\n",
    "except ImportError:\n",
    "    print('geemap package not installed. Installing ...')\n",
    "    subprocess.check_call([\"python\", '-m', 'pip', 'install', '-U', 'geemap'])\n",
    "\n",
    "# Checks whether this notebook is running on Google Colab\n",
    "try:\n",
    "    import google.colab\n",
    "    import geemap.eefolium as emap\n",
    "except:\n",
    "    import geemap as emap\n",
    "\n",
    "# Authenticates and initializes Earth Engine\n",
    "import ee\n",
    "\n",
    "try:\n",
    "    ee.Initialize()\n",
    "except Exception as e:\n",
    "    ee.Authenticate()\n",
    "    ee.Initialize()  "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Create an interactive map \n",
    "The default basemap is `Google Satellite`. [Additional basemaps](https://github.com/giswqs/geemap/blob/master/geemap/geemap.py#L13) can be added using the `Map.add_basemap()` function. "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Map = emap.Map(center=[40,-100], zoom=4)\n",
    "Map.add_basemap('ROADMAP') # Add Google Map\n",
    "Map"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Draw any shapes on the map above using the Draw Control."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Retrieves ee.Feature() of the last drawing object.\n",
    "Map.draw_last_feature"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Retrieves ee.Feature() of all drawing objects.\n",
    "Map.draw_features"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Clipping Earth Engine Image layer with the Draw Control "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import ipywidgets as widgets\n",
    "from ipyleaflet import WidgetControl\n",
    "from geemap import geojson_to_ee\n",
    "\n",
    "Map = emap.Map(center=[40,-100], zoom=4)\n",
    "Map.add_basemap('ROADMAP') # Add \n",
    "\n",
    "# Add Earth Engine dataset\n",
    "image = ee.Image('USGS/SRTMGL1_003')\n",
    "\n",
    "# Set visualization parameters.\n",
    "vis_params = {\n",
    "  'min': 0,\n",
    "  'max': 4000,\n",
    "  'palette': ['006633', 'E5FFCC', '662A00', 'D8D8D8', 'F5F5F5']}\n",
    "\n",
    "# Get basemap layers\n",
    "base_layers = Map.layers\n",
    "\n",
    "# Add Earth Engine DEM to map\n",
    "Map.addLayer(image, vis_params, 'SRTM DEM')\n",
    "\n",
    "# An empty list for storing drawing geometries\n",
    "feat_list = []\n",
    "\n",
    "# Get the DrawControl\n",
    "dc = Map.draw_control\n",
    "\n",
    "# Handle draw events\n",
    "def handle_draw(self, action, geo_json):\n",
    "\n",
    "    geom = geojson_to_ee(geo_json, False)\n",
    "    feature = ee.Feature(geom)\n",
    "    feat_list.append(feature)\n",
    "    collection = ee.FeatureCollection(feat_list)\n",
    "    clip_image = image.clipToCollection(collection)\n",
    "    \n",
    "    Map.layers = base_layers[:3]\n",
    "    Map.addLayer(clip_image, vis_params, 'SRTM DEM')\n",
    "#     Map.addLayer(ee.Image().paint(collection, 0, 2), {'palette': 'red'}, 'EE Geometry')\n",
    "    Map.addLayer(collection, {}, 'Drawing Features')\n",
    "\n",
    "dc.on_draw(handle_draw)\n",
    "\n",
    "# # Add a button to the map\n",
    "# button = widgets.Button(description=\"Clear drawings\")\n",
    "# btn_control = WidgetControl(widget=button, position='bottomright')\n",
    "# Map.add_control(btn_control)\n",
    "\n",
    "# # Handle click event\n",
    "# def on_button_clicked(b):\n",
    "#     dc.clear()\n",
    "\n",
    "# button.on_click(on_button_clicked)\n",
    "\n",
    "Map"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Print out the geojson of the last drawing object\n",
    "dc.last_draw"
   ]
  }
 ],
 "metadata": {
  "anaconda-cloud": {},
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.8.2"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 1
}
